What kind of medium in biological filters helps reduce poor tastes and odors in water?

The correct answer is coarse activated carbon, which is specifically designed to adsorb impurities and contaminants that contribute to poor tastes and odors in water. Activated carbon has a highly porous structure, which increases its surface area, allowing it to effectively capture and hold various organic compounds, chemicals, and odors that can adversely affect water quality.

In biological filters, coarse activated carbon plays a crucial role in enhancing the treatment process due to its ability to remove volatile organic compounds (VOCs) and other taste-and-odor-causing substances. By using activated carbon, water treatment systems can significantly improve the aesthetic qualities of water by making it more palatable and pleasant to the senses.

While fine sand, anthracite coal, and coagulated floc can play roles in water filtration and treatment, they do not possess the same level of efficacy in mitigating taste and odor issues as coarse activated carbon does. Fine sand is primarily used for physical filtration, while anthracite coal is often utilized for its filtration properties but lacks the targeted adsorption characteristics required for taste and odor control. Coagulated floc mainly addresses turbidity and suspended solids through the process of aggregation rather than effectively targeting organic contaminants responsible for bad tastes and smells.